1. Field of the Invention
Embodiments of the present invention relate to an image display apparatus, an image display method, an image display program and a recording medium.
2. Description of the Related Art
Conventionally, images are generally searched by keywords by specifying textual data preassocited with the images. However, in the case where there is no textual data associated with images or such associated textual data is invalid, it is common practice that thumbnails of images are displayed in a list format and images are visually searched by eye.
A common method used when there are a great number of images subject to such eye searches is to limit the number of images displayed on a monitor to 30 or so, for example, and view all images by scrolling both in a vertical and a horizontal direction (see FIG. 1). FIG. 1 shows a first example of a conventional screen display for image search. This technique has an advantage of providing a high level of visibility since each image is displayed in a sufficiently large size; however, also has a disadvantage of not being able to provide a view on all images at one time.
There is another technique in which the display dimensions per image are reduced, thereby displaying all images at one time, as shown in FIG. 2. FIG. 2 shows a second example of a conventional screen display for image search. This technique provides a macroscopic, simultaneous overview of all images, and particularly if the images are classified based on visual characteristics, it is easy to find a target image. Specifically, a target image can be found, for example, by spotting certain images according to image characteristics and the like while having a macroscopic overview of all the images and then zooming in around the images by a zooming operation (here, a case is considered where multiple images are simultaneously zoomed in). According to this technique, however, there is a disadvantage that the display dimensions of each image become smaller as the total number of images on the screen increases. If the number of images on the screen further increases, the images may overlap one another.
Thus, the visibility of each image and the macroscopic visibility of all images counteract each other; however, in the case where the images are classified based on visible characteristics, for example, it is possible to achieve a good balance between these two.
For example, consider a case where images are classified into some groups, as shown in FIG. 3 (there are various possible group classifications for different purposes, such as classification based on similarity of visual characteristics of images, classification based on closeness of dates on which image files were created, and classification according to creators of image files). FIG. 3 shows a third example of a conventional screen display for image search.
This technique makes it possible, if there are a large number of images, to display only a representative image for each group, as shown in FIG. 4, or to display only a foreground image (i.e. an image on which no other images are superimposed) for each group. FIG. 4 shows a fourth example of a conventional screen display for image search. This technique allows a good balance between the group-based macroscopic visibility and the visibility of the representative images. Therefore, with the technique, it is possible to, while having a macroscopic overview of all images on the basis of representative images, spot a certain image according to image characteristics or the like.
Conventional screen display techniques for image search have been described above, and Japanese Laid-open Patent Application Publication No. 2004-178384, for example, discloses a technology pertaining to a content search method and the like which allow searching for a desired content while providing a comprehensive overview of a large number of content without narrowing the macroscopic visibility on the display screen.
Japanese Laid-open Patent Application Publication No. 2004-258838 discloses a technology pertaining to an information search method that allows easily searching for target information in a short period of time. Japanese Patent Publication No. 3614235 discloses a technology pertaining to an information seeking method and the like for efficiently searching a large amount of information.
In the case of adopting a screen display configuration as shown in FIG. 2 or FIG. 4—that is, a screen display configuration that allows the user to spot a certain image according to image characteristics and the like while having a macroscopic overview of all images and then to zoom in around the spotted image by a zooming operation (here, a case is considered where multiple images are simultaneously zoomed in), blank spaces (i.e. areas with no images displayed) are formed between the representative images. Conventionally, such non-display areas due to an image zooming operation are not effectively used, and therefore further improvement in the visibility of a single image and the macroscopic visibility of multiple images cannot be achieved.